It has been proposed to produce a core for a heat exchanger such as a radiator for a motor vehicle, by making an assembly which comprises thin cooling tubes and fin elements in an alternate relationship. The cooling tubes are usually made of copper or brass. The fin elements are then usually manufactured of tapes of copper or brass. During the manufacure of the assembly the cooling tubes and the fin elements are tinned and are then joined together by a soldering process. The fin elements, which in the manufactured assembly consist of corrugated copper or brass tapes, should be manufactured of a very thin material in order to achieve a high efficiency in the heat exchangers. However, if a very thin tape is used for the fin elements it is found that the tape is difficult to handle due to its flexibility and fragility, and this makes the manufacture of the assembly very difficult. Thus, to ensure satisfactory manufacture, it has hitherto been found necessary to make the fin elements of a thicker tape than is desirable for high efficiency of the resultant heat exchanger. Even with the use of such thick tapes it has not been possible to achieve a fully automatic assembly of the cooling tubes and the fin elements. Instead extensive manual work has been required, resulting in high manufacturing costs.
An example of such prior methods are described in British patent specification No. 1,449,296, which discloses a conventional method of constructing a heat exchanger core wherein tubes and fins are manually assembled in a jig, the assembly then being soldered, and which also describes a method in which corrugated fin elements are blown along a passage from a hopper to a station where the fin elements are stacked with tubes. The fin elements must be made of a strip of appropriate thickness to be able to withstand being pneumatically blown along a passage without being damaged. Also the described feeding systems operate slowly, and thus only a slow rate of manufacture can be achieved. British patent specification No. 1,525,761 discloses a similar method in which corrugated fin elements are pneumatically blown along a passage.
International patent application No. PCT/SE79/00153 published under International Publication No. WO80/00228 on Feb. 21, 1980 discloses a further method in which tubes are alternated with intermediate assemblies which comprise two pleated strips which are interconnected by a further flat strip. These intermediate assemblies must be made before the described process is commenced, and the overall procedure is therefore costly.